We now warn:
* `expr.field` when `expr` may not be a map
* `expr.call()` when `expr` may not be an atom
* `expr.call(...)` when `expr` may not be an atom
* `&expr.foo/1` when `expr` may not be an atom
Furthermore, we lay down the ground work for checking undefined
and deprecation warnings across unions. For example, if you write
this code:
mod = if something?, do: Foo, else: Bar
mod.some_function()
In the future, it will warn if any of Foo OR Bar do not define the relevant function.
Finally, we improve pretty printing of maps and aliases in types.
José Valim
514355f3d9